The present invention relates to medical devices and more particularly to a catheter used in the surgical removal of gall stones.
A relatively common, and troublesome, surgical procedure is the removal of "gall stones" caused by the concentration of bile.
Bile is a digestive juice secreted by the liver. The bile aids in the emulsification (dispersion), digestion and absorption of fat. The main constituents of the bile are bile salts (sodium glycocholate and sodium taurocholate), pigments (biliverdin and bilirubin) and cholesterol. Bile is stored, when not used, in the gall bladder, where it occasionally stagnates and forms concentrations of "stones" and is liable to infection.
The liver and gall bladder are connected to slender ducts (tubes) which are joined to the "bile duct" or the "common bile duct". The common bile duct is formed by the junction of the ducts leading from the liver and the gall bladder. The bile is delivered by the common bile duct (tube) to the first part of the small intestine (duodenum), which is the part at the outlet of the stomach.
The surgical removal of the gall stones is regarded as a relatively delicate and difficult surgical procedure. The surgeon should remove all the stones from the common bile duct. Yet the surgeon is unable to see into the common bile duct during the operation. If bile stones, or their particles, are not removed, they may form the nucleus of new stones which may require a later operation, months or years later. To avoid leaving any stones, or their particles, it is the accepted surgical practice to take a set of X-ray pictures after the surgeon has removed the stones. The X-ray pictures will show if any stones or stone particles remain, as well as their number and their location. If any stones or particles remain, the operation may continue and the patient may immediately be operated upon to remove them.
However, it is very difficult to obtain clear X-ray pictures (roentgenograph) of the common bile duct, i.e., called "cholangiography", even during an operation. To obtain worthwhile cholangiography pictures, a suitable X-ray sensitive liquid, called "contrast liquid" or "contrast", is introduced into the common bile duct and retained in the duct while the X-ray picture is taken. One method of temporarily retaining the contrast is to temporarily sew the duct shut to retain the contrast liquid in the duct while the X-ray pictures are taken. That method, however, is relatively slow and cumbersome and may, in some cases, injure the duct tissue.